You could just as easily use a second template for these pages. Modify the main template to fit with your alternate structure, which could also be a static resource. In fact, I prefer the templates to be static so that I can edit outside of MODX.
You could adjust your templates to use chunks for your global sections so you can change heads and footers on the fly.
Make the chunks static as well, if you like. In fact, your Wayfinder menu could be a chunk, which you could then use in the site_header chunk (handy if you had two different Wayfinder calls to use).
Insert the
into a static file where appropriate for the mid section of the page.
Then your template itself would look something like this:
[[$site_header]]
[[$basic_page]]
[[$site_footer]]
And your alternate template could be:
[[$alt_site_header]]
[[$alt_page]]
[[$site_footer]]
☆ A M B ☆
☆ A M B ☆